1. Field of the Invention
The present invention relates generally to elevator control mechanisms, and more specifically to a cable guide for retaining the control, communication, power, and other cables extending from the base of the structure to the elevator car (commonly called xe2x80x9ctrailing cablesxe2x80x9d). The present guide may be used with virtually any elevator structure, but is particularly useful with elevators of tall latticework structures (e.g., tall television antenna towers) where the trailing cable would otherwise be subject to deflection by the wind. The present invention provides secure cable management for elevators operated by hard wired, direct connection cables.
2. Description of the Related Art
Elevator cables in relatively low structures conventionally comprise hard wired trailing cables extending between the base of the elevator structure and the elevator car. These elevator systems can be either cable hoisted or rack and pinion driven. However, with the development of taller structures, the use of cable hoisted systems became the only feasible system, since there was no way to manage the trailing cables on tall structures.
Since trailing cables could not be used, these elevator systems turned to the use of wireless radio systems to transmit control and communication between the base of the elevator structure and the elevator car. Obviously, if no trailing cable could be used, there could be no means of getting power to an elevator car, such as is needed for a rack and pinion system. Consequently, no rack and pinion systems using a trailing cable can be used on these tall lattice structures. (The present inventor knows of one system which uses a gas driven generator to provide power to the drive motor on a rack and pinion system. However, this has not become widely used or popular, for obvious safety reasons.)
This has particularly been the case with elevators used in tall open (latticework) structures, such as television antenna towers and the like, which may extend to well over one thousand feet above the surface. Obviously, some form of elevator, and accompanying lift and control systems, are virtually essential for workers and maintenance crews to travel to the top of the tower. In such open structures, any cables (lift, control, power and communication, etc.) which extend between the base of the elevator shaft and the elevator car, are exposed to the wind, and are subject to being blown against the structure with some accompanying risk of damage. Accordingly, nearly all such structures use a wireless radio link between the elevator car and the base for control. Wireless is used because there currently is no system available for hard wiring a positive circuit for these elevator systems.
These wireless radio controlled systems are subject to interference from outside transmissions and frequency shift, thus diminishing their reliability. The interference risk increases as the elevator and tower height increases, due to the greater line of sight range to the horizon with increasing height. Moreover, while the transceiver at the base may have a reliable power source, the transceiver in the elevator car must be powered by batteries, with the accompanying possibility of low battery power disabling the system. These are serious safety concerns associated with a wireless control system which are eliminated by the present invention.
The present invention provides a solution by providing a means for protecting a hard wired trailing cable in an elevator system. The present invention includes a cable guide in which the power, control, and communication cable(s) is/are routed through a guide which restrains the cable(s) and protects the cable(s) from the wind or other force(s) which might otherwise cause the cable(s) to come in contact with the structure. The present cable guide may also be used to contain a conventional lift cable mechanism for an elevator, in addition to or in lieu of its use for containing communications and/or control cables. The present cable guide system also includes means for precluding jamming or breaking of the cable, in the event the takeup system malfunctions or the cable jams in some manner.
A discussion of the related art of which the present inventor is aware, and its differences and distinctions from the present invention, is provided below.
U.S. Pat. No. 2,017,372 issued on Oct. 15, 1935 to James J. Morrison, titled xe2x80x9cGuideway,xe2x80x9d describes a device for holding control cables within a guideway immediately adjacent the elevator car, to preclude their moving outwardly from the guideway and coming into contact with the car. Morrison recognizes the problem of the relatively slack control and/or communication cables moving laterally within the elevator shaft (or xe2x80x9chatch,xe2x80x9d as he calls it). However, the Morrison guideway system allows the cable to pass therefrom at any point, and Morrison requires a roller at the bottom of the elevator car to bear against the cable within the guideway, to hold the cable within the guideway only at that point in order to preclude escape of the cable from the guideway at that point and possible contact with and damage due to the moving elevator car. Morrison does nothing to retain the cable within the guide at other locations along the guide. In contrast, the present system retains the cable within the guide at all points except immediately adjacent to the car, where the cable bundle narrows to pass through the gap in the side of the guide. This is possible because the cable moves within the guide in the present system, whereas the cable is relatively stationary (excepting the moving loop) in the Morrison system. In the Morrison system, the slot or gap in the side of the guide must be sufficiently large to allow the cable bundle to pass therethrough at any location therealong, whereas the present guide need only have a slot sufficiently wide to allow the smaller end of the cable to pass therethrough.
U.S. Pat. No. 3,295,832 issued on Jan. 3, 1967 to John H. Fowler, titled xe2x80x9cCable Guide Means,xe2x80x9d describes a relatively short guide having a longitudinal slot therein sufficiently wide for a cable contained therein, to pass therethrough. A conical or funnel-shaped component is attached to each end, with the funnel ends also having lateral cable passage slots therethrough. The slots of the funnel ends are turned so they are not in registry with the slot of the guide, thereby holding the cable within the guide. The Fowler device thus teaches away from the present invention, as the cable cannot pass through the wall of the guide at all, but can only pass from either end of the Fowler guide.
U.S. Pat. No. 3,344,888 issued on Oct. 3, 1967 to Edward J. Connelly et al., titled xe2x80x9cElevator Car, Its Machine Room, And An Elevator Traveling Cable Including Both Electrical And Fluid Conductors Connected Therebetween,xe2x80x9d describes a cable construction and suspension means in which a plurality of cable casing strands or wires are secured to an anchor to support the cable. No cable guide is disclosed.
U.S. Pat. No. 3,662,862 issued on May 16, 1972 to Harry S. Poller, titled xe2x80x9cGuide Rope Stabilizer,xe2x80x9d describes pairs of flexible shoes which secure a guide rope within a guide channel attached to an elevator car. The shoes or stabilizers can flex out of the way when the car moves upwardly or downwardly in the shaft, as the guide channel encounters a fixed guide along the guide rope. The guide ropes in the operating environment of the Poller device are fixed at each end, and do not move, as do the cables in the elevator mechanism of the present invention. The elevator car in the Poller system moves upwardly and downwardly along the fixed guide ropes, with the guide channel being affixed to the elevator car and the guide ropes being fixed relative to the elevator shaft. This is generally opposite the present system, where the guide is fixed to the elevator shaft and the cable(s) move(s) upwardly and downwardly within the fixed guide. Poller does not provide any means for his guide ropes to exit a guide and attach to the elevator car, as the guide ropes of the Poller system do not attach directly to the car nor do they provide any form of electrical control or communication power or signal to the car.
U.S. Pat. No. 3,665,270 issued on May 23, 1972 to Peter J. H. Ayers, titled xe2x80x9cElectric Transducers For Tension Control In A Winding Device,xe2x80x9d describes a transducer mechanism incorporating a xe2x80x9cdancer armxe2x80x9d which rides upon the filament or web sheet being wound. The arm communicates with an electromechanical mechanism which in turn increases tension in the filament or web as slack forms, and decreases tension as slack decreases. The Ayers ""270 transducer disclosure is incorporated herein by reference, as exemplary of such transducer means. The present elevator mechanism may use a similar transducer mechanism driven by the movement of an idler pulley around which the cable is wrapped, to act as a slack cable control in the cable takeup and feed reel for the system.
U.S. Pat. No. 3,885,773 issued on May 27, 1975 to Thomas L. Dunkelberger, titled xe2x80x9cMagnetic Cable Takeup Device,xe2x80x9d describes a system much like that described in the Morrison ""372 U.S. Pat. No., discussed further above. However, Dunkelberger provides a series of magnets along the cable guide, with a series of magnetically attractive bands or the like being attached to the cable(s). The magnets hold the cable(s) within the guide due to the magnetic attachments to the cable(s). Otherwise, the Dunkelberger system is similar to that of the system of the Morrison ""372 U.S. Pat. No., with a roller extending from the elevator car and bearing against the cable(s) within the open guide to hold the cable(s) in place adjacent to the elevator car. As in the Morrison system, the cable ends of the Dunkelberger system are fixed, and do not travel in a fixed guide as they do in the case of the present invention.
U.S. Pat. No. 4,058,186 issued on Nov. 15, 1977 to Clyde M. Mollis, titled xe2x80x9cElevator system With Retainer Device For Plurality Of Traveling Cables,xe2x80x9d describes a retainer which wraps about a single cable, with one end then extending to wrap about one or more adjacent cables to secure the cables together in a single bundle. Mollis does not disclose a cable guide. The Mollis cable is stationary relative to the elevator shaft, and does not move upwardly or downwardly within a guide in the shaft, as does the cable of the present mechanism. If the Mollis cable were to move relative to the shaft or guide, the retainers thereon would likely snag within the shaft, or within the guide, if such were provided.
U.S. Pat. No. 5,398,781 issued on Mar. 21, 1995 to Joachim Bailed et al., titled xe2x80x9cCable Tensioning Device For Elevators,xe2x80x9d describes different embodiments of a lift cable tensioning device incorporating a rocker, with one end of the lift cable attached to a relatively larger radius arcuate portion of the rocker and the opposite cable end attached to a relatively smaller radius arcuate portion of the rocker. Cable tension varies as the rocker rotates about an arc, as the cable is paid out or drawn in to operate the elevator. The Bailed cable tensioner may be placed with the counterweight, or with the elevator car as desired. However, no cable guide means is disclosed by Bailed et al., nor is any means provided for stopping travel in the event of a cable jam, as provided by the present elevator mechanism invention.
British Patent Publication No. 1,559,460 published on Jan. 16, 1980 to Mitsubishi Denki Kabushiki Kaisha, titled xe2x80x9cElevator Apparatus With A Hanger For Travelling Cable,xe2x80x9d describes a specific end configuration for the traveling cable (i.e., control and communications cable) in an elevator shaft. The cable of the Mitsubishi disclosure has a central steel structural support member which is surrounded by electrical wiring bundled therewith. It is stated that the cable will have a tendency to twist due to the twist of the individual support cable strands and wrap of the electrical wiring, depending upon the location of the elevator car and thus the relative lengths of the two free ends of the cable. Mitsubishi controls this twist by separating the structural cable and electrical wiring from one another for a predetermined length, allowing the free structural cable end to absorb the cable twist. Mitsubishi does not disclose any form of cable guide, which would provide control of any cable twist which might be developed. Moreover, suspension of the traveling cable of the present elevator mechanism is by means of a grip sleeve around the exterior of the electrical wire bundle, rather than by a central structural support cable, as in the Mitsubishi disclosure.
Japanese Patent Publication No. 6-321,457 published on Nov. 22, 1994 to Hitachi Ltd. describes (according to the drawings and English abstract) a series of rectangular section channels affixed to the walls of an elevator shaft for preventing lateral movement of elevator control cables therein. The Hitachi Patent Publication does not disclose a continuous cable guide for each cable, as provided by the present invention, nor does it disclose any means of retaining the cable within the guide, excepting a relatively short length extending from the guide to the elevator car, as provided by the present elevator mechanism.
Finally, Japanese Patent Publication No. 10-182,034 published on Jul. 7, 1998 to Mitsubishi Electric Corp. describes (according to the drawings and English abstract) a system for moving the junction box of the traveling cable attachment to the elevator shaft wall. This has the benefit of reducing the required length of traveling cable extending from the junction box to the elevator car. However, no cable guide is disclosed in the ""034 Japanese Patent Publication, for restraining a cable therein. The movement of the junction box along the elevator shaft wall, would preclude such a cable guide installed along the shaft wall, in any event.
None of the above inventions and patents, taken either singularly or in combination, is seen to describe the instant invention as claimed. Thus an elevator mechanism solving the aforementioned problems is desired.
The present invention is an elevator mechanism, and more particularly a system for restraining movement of traveling power, control, communications, and/or lift cables in an elevator shaft or structure. The present system includes a continuous guide for the cable, with the cable exiting the guide adjacent to the elevator car and being restrained therein along the remainder of its length.
The present guide includes a continuous slot formed therein, with the cable having a diameter larger than the slot about the majority of the cable length. This precludes passage of the cable through the slot, retaining the cable within the guide except for the narrower end of the cable adjacent the elevator car, where the cable can pass through the slot to extend to the elevator car.
The present invention also includes novel means for suspending the end of the cable adjacent the elevator car, as well as a linear transducer for controlling cable feed and takeup and stop means for shutting down the system in the event of a cable or takeup reel jam. The present cable control system may be used with virtually any type of elevator, but is particularly well suited for use with elevators in relatively tall, open structures such as television transmission antenna towers and the like, where the cable would otherwise be subject to lateral displacement due to wind gusts. The present elevator mechanism allows cable control and communications systems to be used in such structures, rather than relatively unreliable radio control and communication systems with cable hoist systems, and allows the use of rack and pinion systems with the motor being attached directly to the elevator car and powered by the cable in the guide.
Accordingly, it is a principal object of the invention to provide an elevator mechanism for retaining an elevator control, communications, power, and/or lift cable(s) therein, and precluding lateral movement of the cable(s) from the guide.
It is another object of the invention to provide means for supporting the end of the cable adjacent to the elevator car, and for reducing the diameter of the cable at its end to allow the cable to pass through a slot in the wall of the cable guide.
It is a further object of the invention to provide a mechanism for controlling an elevator cable(s) in an elevator shaft which is adaptable to any practicable elevator system, including rack and pinion drives and lift cable drive systems, and which is particularly adaptable for use with elevators used in tall, open latticework structures.
Still another object of the invention is to provide an elevator mechanism including means for stopping the system in the event of a cable or cable reel jam.
It is an object of the invention to provide improved elements and arrangements thereof for the purposes described which is inexpensive, dependable and fully effective in accomplishing its intended purposes.
These and other objects of the present invention will become readily apparent upon further review of the following specification and drawings.